package cn.xcu;

import java.util.Scanner;

    public class chap5 {
        public static void main(String[] args) {
            Scanner input = new Scanner(System.in);

            int sum = 0;
            for (int i = 0; i < 10;i++)
            {
                int number = input.nextInt();
                sum+=number;
            }
            double average = (double)sum/10;
            System.out.printf("%.2f",average);

        }
    }

